i have a few questions about the requirement of an initramfs when /usr is on a separate partition. I dont have initramfs yet and there are no (aparent) problems.
1) Is there a way to avoid initramfs when /usr is on a separate partition?
2) Where can i find more information about the internals of the early boot phase, where initramfs comes into play?
3) I know initramfs as a way to provide modules that are needed to access the block device where the root partition is, but i have these built in. What else would i use it for?
4) I could just follow http://wiki.gentoo.org/wiki/Dracut but how can i know if initramfs works, because my system seems okay even without initramfs.

I found that genkernel is able to create an initrd image and will early-mount all filesystems given in /etc/initramfs.mounts.
However it seems that the init-script from initramfs is unable to cope with hexadecimal device numbers in the kernel commad line, see /usr/src/linux/Documentation/kernel-parameters.txt (root= entry). Because root=/dev/sda5 works but root=805 does not but is a valid way to provide the root device. This is a problem whe you use lilo, becaus lilo will translate your root=/dev/sdXY into the correct hex number.
Links i used:

I keep an initramfs that mounts user handy in case anything breaks. So far, everything works. A failed boot just splashes a lot of failure messages at you. The solution is simple: log in, reboot, change boot option, reboot. losing /usr will cripple the system, not kill it._________________First things first, but not necessarily in that order.

ulenrich, do you think genkernel will be dropped in future? I use genkernel only to create the ramdisk, because i tend to manually install the kernel.
The bug [1] i filed is still unconfirmed. I will take a closer look at Dracut.

Etal, separate /usr without initrd using busybox is quite neat, i will try that too.

On then contrary genkernel is worked on very hard recently. As some stated it is not hard to build your own initramfs - this is true for the most simple case. Dracut has a very fine infrastructure which will fit for all cases.

But Dracut was initiated by some Fedora guys. Redhat is hated by most Gentoo developers. I don't know why._________________fun2gen2

I have separate /usr and no initramfs (with eudev), everything works properly without any additional configuration. The separate /usr is broken thing is basically a myth, although it does break some rare use cases._________________"To design the perfect anti-Unix, make all file formats binary and opaque, and require heavyweight tools to read and edit them." - The Art of Unix Programming

I have separate /usr and no initramfs (with eudev), everything works properly without any additional configuration. The separate /usr is broken thing is basically a myth, although it does break some rare use cases.

same with latest udev._________________Only two things are infinite, the universe and human stupidity and I'm not sure about the former - Albert Einstein
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